/************************************************************************/
/*                     Copyright declaration                            */
/*                         (3-clause-BSD)                               */
/************************************************************************/

/*
* Copyright (c) 2009, Roc King
* All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
*     * Redistributions of source code must retain the above copyright
*       notice, this list of conditions and the following disclaimer.
*     * Redistributions in binary form must reproduce the above copyright
*       notice, this list of conditions and the following disclaimer in the
*       documentation and/or other materials provided with the distribution.
*     * Neither the name of the OwnWaterloo,Roc King nor the
*       names of its contributors may be used to endorse or promote products
*       derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS AND CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <assert.h>
#include <string.h>

#include "ccurry/stdcall2stdcall_definition.h"


#ifndef CALLBACK_CURRYING_NO_PORTABILITY_SIZE_CHECK
static const char g_32bit_check[sizeof(uintptr_t)==sizeof(uint32_t)?1:-1] = {0};
#endif  /* #ifndef CALLBACK_CURRYING_NO_PORTABILITY_SIZE_CHECK */

void stdcall2stdcall_initialize(stdcall2stdcall_closure* closure)
{
    /** the layout of machine code */
    static const stdcall2stdcall_closure layout= {
        {0x58},                         /* pop eax */
        {0x68}, {0xcc,0xcc,0xcc,0xcc},  /* push fixed argument */
        {0x50},                         /* push eax */
        {0xe9}, {0xcc,0xcc,0xcc,0xcc},  /* jmp applied function */
    };
    /* 0xcc is the intermit 3 instruction */

    if (!closure) {
        assert(0);
        return;
    }

    memcpy(closure,&layout,sizeof(*closure));
}

void stdcall2stdcall_set_function(stdcall2stdcall_closure* closure
                                 ,uintptr_t applied_function)
{
    uintptr_t offset_to_function = 0;

    if (!closure) {
        assert(0);
        return;
    }
    offset_to_function = applied_function - 5 - (uintptr_t)closure->jmp;
    memcpy(closure->offset_to_function,&offset_to_function
        ,sizeof(closure->offset_to_function));
}

uintptr_t
stdcall2stdcall_get_function(const stdcall2stdcall_closure* closure)
{
    uintptr_t offset_to_function = 0;

    if (!closure) {
        assert(0);
        return 0;
    }

    memcpy(&offset_to_function,closure->offset_to_function
        ,sizeof(offset_to_function));
    return offset_to_function + 5 + (uintptr_t)closure->jmp;
}

void stdcall2stdcall_set_argument(stdcall2stdcall_closure* closure
                               ,uintptr_t fixed_argument)
{
    if (!closure) {
        assert(0);
        return;
    }

    memcpy(closure->argument,&fixed_argument,sizeof(closure->argument));
}

uintptr_t
stdcall2stdcall_get_argument(const stdcall2stdcall_closure* closure)
{
    uintptr_t argument = 0;

    if (!closure) {
        assert(0);
        return 0;
    }

    memcpy(&argument,closure->argument,sizeof(argument));
    return argument;
}
